A HEARTENING TWIST
How groundbreaking technology could revolutionize transplants
On Sept. 24, doctors filed into a bustling Houston Methodist operating room to gaze at the novelty of a heart that appeared to beat on its own. A close look revealed the secret — a waist-high apparatus that looked like an office-style copy machine, housing a bag of blood to supply oxygen through two tubes fastened to key arteries.
Dr. Erik Eddie Suarez, a cardiothoracic surgeon with the Houston Methodist DeBakey Heart and Vascular Center, liked what he saw: a strong beat, good blood flow and low amounts of acid. This would be a fine organ, he thought, for 55-year-old Kenneth Morris, who lay on an operating table next door. The former electrician finally could put a decade of debilitating heart disease behind him. His wife, April, prayed to see him jog again.
But a difficult operation lay ahead for Suarez and the surgical team.
The machine, known as a TransMedics Organ Care System, represents the modernization of heart transplantation in Houston, expanding the number of potential donors by up to 30 percent amid a consistent shortage of available organs. Without it, Morris' time on the waitlist for a heart could have ballooned by weeks or months, his risk of becoming too sick for a transplant increasing with each passing day.
Since transplants became the standard treatment for end-stage heart failure in the 1980s, heart donations in
the U.S. have been confined to brain-dead patients. Their hearts have been the safest to use because surgeons can see the still-beating organ inside the body — an important step before a transplant — and more easily manage the retrieval process to prevent long-term damage.
Colloquially called “heart-ina-box,” TransMedics technology allows Methodist and other hospitals around the country to turn to a wider patient population: people who died because their heart stopped. The machine essentially brings the heart back to life by mimicking the body’s natural function, so surgeons can safely retrieve the organ and preserve it longer. Methodist is the first Houston hospital to use the heart system, which received FDA approval last year. Baylor St. Luke’s Medical Center has performed lung transplants with the machine and expects to use it for hearts soon.
Morris would be the second patient in Houston to receive a heart off the machine if all went well. His advanced coronary artery disease — and a previous heart surgery — left him with scarring that could prove challenging for Suarez and his team. Morris also was overweight, with excess tissue that Suarez would have to carefully navigate around while making his cuts.
One wrong incision could be fatal.
Retrieval
Earlier that day, at another hospital outside the Houston area, doctors extubated Morris’ donor, who had suffered irreversible brain damage, declaring death soon after. The moment the heart stopped, the clock started for Dr. Dewei Ren, a cardiothoracic surgeon on Houston Methodist’s organ retrieval team.
Ren would have 30 minutes to access the heart and begin the preservation process. One minute longer, and the organ would be considered useless. Warm ischemia time — or the amount of time an organ sits at body temperature with little to no blood supply — is associated with lower survival rates for heart recipients.
So Ren had to act quickly. Slow is smooth, smooth is fast, Ren thought as he cut through the donor’s skin and breastbone. Seven minutes ticked by.
When he saw the motionless heart, he sunk a tube into a large vein to draw blood, which would bring the heart back to life on the machine. Within 10 minutes, he injected a solution to protect the organ from damage, buying himself more time as he cut away the critical blood vessels.
Still on schedule, he thought. It took Ren another half hour to attach the heart to the machine. He tied off exposed veins and plunged a large tube down the main artery, which would deliver blood into the heart, and another into the pulmonary artery, which would carry it out. Then Ren clutched the organ and squeezed, a signal to the heart to start beating.
As it swelled with blood and nutrients, Ren attached a pacemaker to the heart’s lower left chamber and completed a series of tests, largely aided by the machine. He took lactate acid readings and assessed the strength of the beat and the blood flow pressure.
He texted results to Suarez. No contusions. No surgical injuries. No blockages. Both surgeons were satisfied. Ren and the other members of the retrieval team rolled the machine out and boarded a plane to Houston.
New technology
Before TransMedics technology, transplant retrieval teams preserved hearts from braindead patients in an icebox, with limited time to travel to the recipient hospital. Hearts are viable only up to about four hours on ice, so the location of the donor is a major factor with traditional methods.
The limits of heart donation encouraged TransMedics founder Waleed Hassanein to begin looking for solutions in the 1990s.
He started working on the project that would become the organ care system as a cardiothoracic surgeon at Brigham and Women’s Hospital at Harvard Medical School. He had planned to take a one-year sabbatical to bring the technology into clinical practice. It has taken nearly 25 years, with eight FDA trials, to finally realize his goal.
During the FDA review process, transplant centers in Australia, the United Kingdom and Belgium began using the technology for hearts with early success. Baylor St. Luke’s also became the first in Texas to use the machine for a lung transplant as part of a clinical trial. Now, the machine is approved for hearts, lungs and livers.
The most recent study of the heart machine, published earlier this year, reported a roughly 94 percent survival rate at six months post-transplant; using traditional methods, with hearts from brain dead patients, the six-month survival rate was about 88 percent. One-year outcomes also proved better for patients who used the machine.
There are some financial limitations.
Hospitals pay a fee of $70,000 to $90,000 per transplant, depending on the organ, to use the machine as part of a TransMedics program, which sends a specialist with the transplant team to help manage the retrieval. That figure is small compared to the average cost of a heart transplant, which generally exceeds $1 million before insurance. The added cost hasn’t stopped Methodist, St. Luke’s and more than 30 other transplant centers nationwide from using the technology, which has allowed transplant teams to use more hearts and fly longer distances when necessary.
For people like Morris, the potential benefits could mean the difference between life and death. The American Heart Association reports up to 20 percent of heart transplant candidates die or become too sick for surgery while waiting for a donor match. Heart transplant candidates in 2021 waited on average 81 days for a heart.
Morris waited two.
The surgery
On the afternoon of Sept. 24, more than a dozen members of Methodist’s medical staff packed into the operating room as blood pooled in Morris’ open chest around his scarred, beating heart.
A rendition of the “House of the Rising Sun” played softly on overhead speakers. Suarez and his assistant, Donell K. Bowen, were in control, but the surgery had been especially time-consuming, as they spent more than an hour separating and cauterizing blood vessels, slowly working their way around the organ’s edges with tiny cuts. They communicated with subtle body language, as Bowen used forceps to clasp blood vessels and nearly indistinguishable flaps of red tissue for Suarez to tie off and snip away.
Wearing thick, black-rimmed surgical glasses, Suarez looked up to the corner of the room at Safan Momin, a TransMedics clinical specialist, who had stayed with the machine since it arrived at the hospital nearly three hours earlier.
“You can start prepping the heart,” Suarez told Momin, moments before he removed Morris’ heart, partially coated in yellowy fat, and placed it in a small white container to be sent for further examination.
Momin acted quickly. He drained the blood from the donor heart and placed handfuls of ice over the organ inside its outer case. Finally, he turned off the pump as the color of the heart changed from a deep red to a pale yellow and purple. Suarez and Bowen approached, gloved hands in the air, to handle Morris’ new heart for the first time.
It was smaller than his old one, but the surgeons had techniques to make up for the size difference. It was a beautiful heart, Suarez thought as he began the hourslong process of tedious suturing, allowing the organ to again flow with life inside Morris’ chest.
Morris’ recovery wouldn’t be easy. He faced complications by what doctors believed to be lingering lung damage from a prior COVID-19 infection. But he improved day by day, the heart functioning as well as Suarez had hoped.
April Morris knows her husband faces months of intensive recovery. For now, she is managing her expectations. But the thought of him walking without taking frequent breaks, or driving without having to pull over, or staying awake through a movie night with the kids, gives her hope.